Fuel injection nozzle

ABSTRACT

A dual orifice fuel injection nozzle for gas turbines and the like characterized in that a unitary primary nozzle body clamped between the secondary nozzle body and the nozzle housing provides a primary swirl passage and a secondary swirl passage leading respectively to a primary swirl chamber and primary discharge orifice and to a secondary swirl chamber and annular secondary discharge orifice, the secondary orifice and chamber being defined between said primary and secondary bodies with the latter being screw threaded onto the nozzle housing. A further characterizing feature of the invention is that the secondary fuel supply passage is located centrally of the nozzle tip end of the housing with the primary passage disposed radially outward thereof.

llnited States Patent OSickey [451 Aug. 22, 1972 [54] FUEL INJECTIONNOZZLE [72] Inventor: Lawrence B. OSicke Uni rs't Primary Examiner 'M'Henson wood HeightS, Ohio V6 1 y Assistant Examiner-Michael Y. MayAttorney-Oberlin, Maky, Donnelly and Renner [73] Asstgnee:Parker-Hannifin Corporation,

Cleveland, Ohio 57 ABSTRACT [22] Filed: July 16, 1970 A dual orificefuel injection nozzle for gas turbines 21] App! 55 37 and the likecharacterized in that a unitary primary nozzle body clamped between thesecondary nozzle body and the nozzle housing provides a primary swirl"239/4061; passage and a Secondary Swirl passage leading respec tivelyto a primary Swirl chamber and primary [58] Field of Search ..239/403,404, 405, 406; discharge Orifice and to a Secondary Swirl chamber60/39'74 and annular secondary discharge orifice, the secondav ryorifice and chamber being defined between said pri- [56] ReierencesC'ted I 7 mary and secondary bodies with the latter being screw UNITEDSTATES PATENTS threaded onto the nozzle housing. A furthercharacy tenzmgfeature of the invention is that the secondary 3,443,760 5/1969 SImmOnS..239/403 X fuel supply passage is located centrally f the nozzle o l tl tip end of the housing with the primary passage 4 some a d t dth r f3,024,045 3/1962 Cleminshaw et al...239/404 x pose ta 1 y War e 603,039,701 6/1962 Carlisle ..239/404 X 1 Claim, 2 Drawing Figures FUELINJECTION NOZZLE BACKGROUND OF THE INVENTION In dual orifice fuelinjection nozzles it is a prevalent practice as shown for example in thepatents to Webster et al. US. Pat. No. 3,013,732, and Moebius et al. US.Pat. No. 3,159,971, to provide a nozzle housing having at the nozzle endthereof coaxial primary and secondary fuel supply passages of which theprimary passage is the center one and the secondary passage is anannular passage around the primary passage. In such known constructionsthe primary orifice body has swirl slots on its periphery which definewith the secondary body which is screwed onto or into the nozzlehousing, swirl passages which lead to a secondary swirl chamber andsecondary orifice which is defined between the primary and secondarybodies. Furthermore, to provide the primary swirl slots and primaryswirl chamber leading to the primary discharge orifice the primary bodyis provided with a swirl plug disposed therewithin. In Webster et al.US. Pat. No. 3,013,732 the housing has screwed thereinto a bushing ontowhich the primary nozzle body is screwed and between the busing and theprimary body is a primary swirl plug and has screwed thereonto thesecondary body which forms with the primary body the secondary swirlslots, the secondary swirl chamber, and the secondary annular dischargeorifice. In Moebius et al. U.S. Pat. No. 3,159,971 the primary swirlplug has screw threaded engagement in the housing and in turn, theprimary body is screw threaded on said swirl plug and finally, thesecondary body has screw threaded engagement with the housing to formthe aforesaid secondary swirl slots, chamber, and discharge orificewhile the primary body and swirl plug form therebetween the primaryswirl slots, chamber, and discharge orifice.

SUMMARY OF THE INVENTION Contrary to the foregoing, in the presentinvention the secondary fuel supply passage is located centrally at theend of the nozzle housing with the primary passage being disposedradially outward to one side thereof, whereby when the secondary body isscrewed onto the housing it clamps therebetween a unitary primary bodywhich contains not only the primary swirl slots, primary swirl chamber,and primary discharge orifice, but in addition, the secondary swirlslots which communicate the secondary fuel supply passage with thesecondary swirl chamber and secondary discharge orifice which is definedbetween the primary and secondary bodies.

Other objects and advantages of the present invention will appearhereinafter.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-section view of apreferred embodiment of the present invention; and

FIG. 2 is a cross-section view taken substantially along the line 2-2,FIG. 1.

DETAILED DESCRIPTION OF THE DRAWING The dual orifice injection nozzle 1herein illustrated comprises a housing 2 provided with primary andsecondary fuel supply passages 3 and 4 which, as well known, communicateat their upstream ends with a fuel inlet port and with the downstreamend of a flow divider or variable area valve, not shown herein, thesecondary fuel supply passage 4 terminating in a flare mouth openingcentrally located at the nozzle end of the housing 2, and the primarypassage 2 terminating in an opening which is radially outwardly spacedfrom the secondary opening. 7

The secondary nozzle body and air shroud 5 is screwed onto the end ofthe housing 2 and may be welded thereto as shown, and the unitaryprimary body 6 is clamped between the secondary body 5 and the end ofthe housing 2 to form with the secondary body 5 a secondary swirlchamber 7 and an annular secondary discharge orifice 8, the primary body6 being provided with one or more helical swirl passages 9 therethroughwhich intercommunicate the secondary passage 4 with the secondary swirlchamber 7.

The primary body 6 also has therein one or more tangential swirlpassages 10 which lead from an annular chamber 11 communicating with theprimary passage 3 into the primary swirl chamber 12 which has a centralprimary discharge orifice 14. The end of the primary swirl chamber 12opposite the orifice 14 is closed by a plug 15 in said body 6.

Thus, when the-gas turbine or the like is operating, the fuel passingthrough the primary passage 3 enters the annular chamber 11 and flowsthrough the tangential swirl passage or passages 10 into the primaryswirl chamber 12 for discharge from the primary orifice 14 in finelydivided hollow conical spray form.

As the fuel pressure increases, and as the flow divider (not shown)opens, fuel also flows through the secondary passage 4 and the secondaryswirl passage or passages 9 into the secondary swirl chamber 7 fromwhence the fuel issues in finely divided hollow conical form through theseopndary annular discharge orifice 8 From the foregoing it can be seenthat the present invention provides a very simple form of dual orificefuel injection nozzle 1 involving-basically only two parts, namely, asecondary body 5 and a primary body 6 of which the secondary body 5 isscrew threaded and welded onto the nozzle housing 2. The secondary body5 has a first counterbore 16 of substantially the same diameter as theprimary body 6, said secondary body 5 being effective to clamp theprimary body 6 between the axially spaced apart annular end face 17 ofthe nozzle housing 2 and the bottom 18 of the first counterbore 16. Theunitary primary body 6 contains not only the primary swirl passage 10,but also the secondary swirl passage 9 respectively leading to theprimary swirl chamber 12 and to the secondary swirl chamber 7. Theprimary swirl chamber 12 is, as aforesaid, closed as by means of theplug 15 which is press fitted or otherwise secured into the end of theprimary body 6 to isolate the primary discharge orifice l4 and primaryswirl chamber 12 from the centrally located secondary fuel supplypassage 4. The secondary body has a second counterbore 19 with a bottom20 axially spaced from the end face 17 and from the bottom 18 of thefirst counterbore 16 to form the annular chamber 11 around the primarybody 6 and radially outward of the end face 17, said chamber 11communicating the primary fuel supply passage 3 in the nozzle housing 2with the primary swirl passage 10 in the primary body 6.

I, therefore, particularly point out and distinctly claim as myinvention:

1. A dual orifice fuel injection nozzle comprising a housing having atone end an annular end face and having primary and secondary fuel supplypassages which are open at said one end respectively radially outwardand inward of such end face; a secondary body secured to said housingand having a secondary fuel discharge orifice and first and secondcounterbores with their bottoms axially spaced from each other and fromsuch end face; a cylindrical primary body of diameter less than saidsecond counterbore and substantially equal to said first counterboreclamped between such end face and the bottom of said first counterboreand defining with said secondary body a secondary swirl chamber upstreamof said secondary orifice and defining with said second counterbore anannular chamber around

1. A dual orifice fuel injection nozzle comprising a housing having atone end an annular end face and having primary and secondary fuel supplypassages which are open at said one end respectively radially outWardand inward of such end face; a secondary body secured to said housingand having a secondary fuel discharge orifice and first and secondcounterbores with their bottoms axially spaced from each other and fromsuch end face; a cylindrical primary body of diameter less than saidsecond counterbore and substantially equal to said first counterboreclamped between such end face and the bottom of said first counterboreand defining with said secondary body a secondary swirl chamber upstreamof said secondary orifice and defining with said second counterbore anannular chamber around said primary body and radially outward of suchend face which communicates with said primary fuel supply passage; saidprimary body having a primary discharge orifice coaxial with saidsecondary orifice and a primary swirl chamber upstream of said primaryorifice; said primary body further having circumferentially offsetprimary and secondary swirl passages respectively communicating saidannular chamber with said primary swirl chamber and said secondary fuelsupply passage radially within such end face with said secondary swirlchamber whereby fuel is discharged in conical spray form from therespective primary and secondary orifice.